omitting columns from a data frame
Hi Erin,
As you've seen from the responses so far there are many ways to do it.
I like to do
xm1[setdiff(names(xm1), c("x1", "x2", ...))]
where xm1 is the data.frame, and "x1", "x2", ... are the columns you
wish to exclude. Just another option.
Best,
Ista
On Mon, Jun 20, 2011 at 11:52 PM, Joshua Wiley <jwiley.psych at gmail.com> wrote:
Hi Erin, See inline. On Mon, Jun 20, 2011 at 8:45 PM, Erin Hodgess <erinm.hodgess at gmail.com> wrote:
Dear R People: I have a data frame, xm1, which has 12 rows and 4 columns. If I put is xm1[,-4], I get all rows, and columns 1 - 3, which is as it should be.
Okay, so you know how to use the column number to omit columns.
Now, is there a way to use the names of the columns to omit them, please?
You have all the pieces (the column names, and the knowledge that you can omit columns by their index). Homework: find a way to return the column numbers given the column names (hint). Cheers, Josh
Thanks so much in advance! Sincerely, Erin -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: erinm.hodgess at gmail.com
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
-- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org